It is seen in FIG. 1 of the above mentioned document that the flywheel of the clutch carries at its rear end the reaction plate of a friction clutch, and has a sleeve which extends towards the casing of the internal combustion engine, referred to as the engine, of the motor vehicle. The sleeve carries the rotor of a rotary electrical machine, which is thereby incorporated in the clutch. This machine comprises, in the known way, a fixed stator surrounding the rotor, with an airgap between the inner periphery of the stator and the outer periphery of the rotor.
The front end of the sleeve, which is also the front end of the flywheel, is fixed on the crankshaft of the engine.
The rotor has a significant weight, and, like the reaction plate and the clutch, it is cantilevered from the front end of the sleeve.
As is known, the crankshaft vibrates when the engine of the vehicle is working.
This gives rise to troublesome dynamic knocking effects in the region of the airgap between the stator and rotor, so that the airgap can vary and has to be dimensioned accordingly, which is detrimental to the performance of the machine. In addition, because of the cantilevers, inertias and weights of the rotor and clutch, the crankshaft and its bearings are subjected to strong applied forces, which is detrimental to the mechanical strength and useful life of the crankshaft.
In the embodiment of FIG. 4 in the document FR-A-2 782 355, a constant airgap is obtained by use of a carrier member.
Although that solution is satisfactory, the carrier member increases overall size. In addition, it calls for the use of a ball bearing of large size, interposed radially between the carrier member and the flywheel. The same is true in the embodiment in FIG. 1 of the document U.S. Pat. No. 6,253,437.